Mammalian subjects require a semi-continuous supply of air, such that the oxygen level in the brain is retained above a threshold level. There are many conditions and situations under which the air supply is temporarily stopped or reduced. These may include, but are not limited to, sleep apnea, heart attack, epileptic seizure and drowning. If the subject does not receive oxygen within a number of seconds/minutes, the result can lead to irreversible brain damage, and, in some cases, death.
Many devices and methods have been developed to ensure a continuous air supply to human subjects. However, many of the devices are cumbersome, uncomfortable and lead to patient non-compliance. Other devices are not adapted to deal with patient movement.
Some publications in the field include U.S. Pat. No. 4,305,387, which describes a mouth closure for providing artificial respiration to patients, which consists of a deformable elliptical plate, whose periphery is surrounded by a tube. The tube is formed in the shape of an air hose made of an elastic film with a hose for admission of air. A tube passes through the plate in a central region. The mouth closure is placed in the dentilabial cavity of the patient's upper and lower jaws. The tube, in association with the gums and the lips and cheeks, seals the oral cavity from the outside. A flow of air through the tube therefore enters the respiratory passages of the patient and also passes back from the respiratory passages, through the tube, to the outside. This publication teaches the requirement for a medical professional to fill the airholes, thereby preventing a user from using it just by itself. This device is not self-adaptable.
US Patent Publication No. US2002005201 describes an improved nasal mask, for delivering CPAP therapy to patients. The nasal mask has a sliding engagement to the headgear. The sliding engagement allows substantial relative lateral movement eg: when face is distorted from sleeping on side, while still providing adequate compressive force to avoid side leakage. The sliding engagement also allows easy release from the headgear.
US Patent Publication No. US2003075182 discloses an application device for a breathing mask arrangement, including a base portion, a holding portion structured to support a mask and pivotally mounted to the base portion for pivotal movement about a first pivot axis, a right arm element pivotally mounted to the base portion for pivotal movement about a second pivot axis, and a left arm element pivotally mounted to the base portion for pivotal movement about a third pivot axis. The right and left arm elements are each provided with a contact portion for bearing against a right and a left forehead zone respectively of a mask user. The holding portion, the right arm element, and left arm element can be pivoted with respect to the base portion about the respective first, second, and third pivot axes.
US Patent Publication No. US2003183227 describes a CPAP device and a method for treating sleep apnea, using a head appliance with an oral adaptor comprising a tube partially inserted in a person's mouth and a diaphragm applied over the tube against the mouth, such that the lips are formed into a tight seal with the tube. A nasal seal is described comprising two rollers to which a strap is attached, so that the nasal seal is easily put in place, adjusted and maintained by rolling the rollers on the nose sides or pulling the straps.
US Patent Publication No. US2003089371A describes a mouthpiece for oral delivery of CPAP treatment, which has a vestibular shield for location between the teeth and lips/cheeks of a wearer. The vestibular shield is dimensioned to extend laterally into the buccal vestibule and vertically to overlap the gums. The vestibular shield is formed from a very supple material. A gases pathway is provided through the vestibular shield and may include a hard plastic insert through the shield, including a standard breathing conduit connection at its outer end. A short stub conduit on the outlet side of the shield passes between the wearers upper and lower teeth. A connection for connecting the mouthpiece to a breathing circuit is also provided which reduces the transfer of forces caused by movement therebetween. The connection may include a short length of highly flexible gases conduit, an elbow and a swivel connection.
US Patent Publication No. US2005236003A describes a sleep apnea prevention device which is designed to move the lower jaw forward, keep teeth and lips apart, and guarantee full oxygenation needs with oral airway that is centered in an anterior dental-buccal space shield and wing portion. This, with mouth guard for lower teeth, is all a unit as a single piece of molded plastic or any other material; with said unit modeled from four theoretical portions including a barrier-like anterior portion fitted and anchored between anterior teeth-gums and behind the lips in the anterior buccal space with flanking wing like fins extending in that space laterally back to the upper second molars, thus allowing good retention in place whether mouth is open wide or minimally, or closed or moving side to side. Said shield is functionally tethered at the top front which becomes its fulcrum as it engages the lower teeth with a mouth guard portion and swings the lower jaw forward with bite activity; mouth guard pylon like blocks mounted on the mouth guard superior surface keep the teeth apart and help swing the jaw forward. The barrier in midline supports a nipple like projection which is, actually, a tube-like conduit which keeps the lips apart and becomes an oral airway. This device can be used alone or with CPAP face mask in place and user must coordinate with health provider to insure sleep apnea is only moderate and not just masked and inadequately treated. It usually does help snoring and bruxism.
World Patent Publication No. WO06079149A discloses an oral leak prevention device for patients who use nasal CPAP machines (Continuous positive airway pressure). The device minimizes air escaping through the mouth of patient while they are being pressurized through the nasal passage by the airflow of a CPAP machine. The oral leak prevention device is placed over the mouth and securing straps hold the device in place. The built in valve is to allow the patient to inhale if the CPAP machine should fail but under normal circumstances the valve stops air escaping from the mouth while the patient is sleeping.
US Patent Publication No. US2007131229A relates to a respiratory mask arrangement that can be used in the framework of CPAP therapy for treating sleep-related disturbances, for example. In one embodiment a respiratory mask arrangement comprises a sealing lip device to be placed on the facial surface of a mask user, a covering device which defines a mask interior in cooperation with the sealing lip device, and a respiratory gas conduit unit for delivering respiratory gas to the mask interior that is defined by the covering device and is connected to the nostril and/or oral opening of the mask user. At least some sections of the covering device are embodied as an air-permeable structure.
World Patent Publication No. WO08041237A describes an intra-oral continuous positive airway pressure (CPAP) device that comprises a tube connected to a source of positive air pressure, and a shield connected to, or integrally formed with, the tube and adapted to be inserted within buccal sulci in such a way that facilitates oral cavity sealing. The shield has a central part formed with an aperture in communication with the tube, and right and left longitudinally extending projections adjoining, and of substantial bilateral symmetry with respect to the central part. Each of the projections has adjoining upper and lower regions and each of the regions has adjoining proximal and distal portions, Each of the projections is dimensioned such that a distal portion has a thickness substantially equal to, or greater than, a buccal sulcus potential space gap, and is configured, when inserted within a buccal sulcus, in such a way so as to adhere to the oral mucosa, to occupy the entire volume of buccal sulcus potential space, and to seal the oral cavity.
Despite the advances of the inventions described hereinabove, there is still a need to provide CPAP devices and methods which are less cumbersome and of better ergonomics, thereby providing devices which lend themselves to greater patient compliance.